<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
</body>
</html>
<SCript>
var x = prompt('输入X的值');
var y = prompt('输入Y的值');
if(x >= y){
    alert('最大的数字是'+x);
}else if(y >= x){
    alert('最大的数字是'+y);
};
var a = x;
 x = y;
 y = a;
 alert("x=" + x + "," + "y=" + y )
</SCript>